White Campion (Silene latifolia) is a common wildflower of field margins, hedgerows, waste ground etc. It flowers throughout the summer and this one is hanging in there with a few flowers even in October. The bladder-like seed pods continue to develop which elsewhere on the plant have dried out dry to form a vessel full of seeds.

 S. latifoila is an example of a species that's on the cusp of being an annual, biennial or a short lived perennial depending on conditions. Red Campion (Silene dioica) is more reliably perennial but short lived. Both perpetuate themselves with copious self-seeding. Actually Red Campion is more of a pinkish colour. Where it grows near White Campion they sometimes hybridise to create a pale pink Campion.

 I had always assumed that White Campion is scentless but I have read that it releases its fragrance at night to attract moths.